Usage

This module stores some user contributed themes which can be used
with decorated layouts (such as Tabbed). (Note that these themes
only apply to decorated layouts, such as those found in
XMonad.Layout.Tabbed and XMonad.Layout.DecorationMadness; they
do not apply to xmonad as a whole.)

If you want to use one of them with one of your decorated layouts,
you need to substitute defaultTheme with, for instance, (theme
smallClean).